TDA Research, Inc. (TDA) proposes to develop a new class of inexpensive, reactive reinforcing fillers for methacrylate-based dental resins. Tese fillers promise improvements in resin strength (compressive, tensile, and flexural) and abrasion resistance, which could lead to further replacement of amalgam by composites, even on posterior molar surfaces where composites currently fail due to the high stresses of mastication. These fillers would make resin manufacture safer and cheaper since the silanation step required for current silica fillers could be avoided. They could also make dental restoration safer for the dentist as exposure to the mercury-containing amalgam could be greatly reduced or eliminated. In Phase I, TDA will prepare a series of reactive nanoparticles and incorporate them into a standard hybrid composite methacrylate dental resin. These composite resins will then be tested for strength, water solubility and sorption, as well as working and curing properties. Improvements in composite strength are expected with no deleterious effects on other composite properties. PROPOSED COMMERCIAL APPLICATIONS: In addition to their use in dental restorative resins, these hard reactive fillers could improve the properties of scratch resistant coatings for optical surfaces, abrasion resistant linings, more dimensionally stable acrylate-based rapid prototyping resins used in stereolithography, and acrylic barrier coatings to reduce oxygen permeation into plastic beverage containers. The combined market for reactive acrylic nanoparticles in could be approximately 100 tons/year.